Submarine periscope



ecu 19, 1950 v J. M. STRANG SUBMARINE PERISCOPE 4 Sheets-Sheet 1 Filed 001- 26, 1946 FIG Inventor 3 JBHN Nae-nu STRANG By MK R Altorney ec. 19, 1950 J. M. STRANG 2,534,884

SUBMARINE PERISCOPE Filed Oct. 26, 1946 4 Sheets-Sheet 2 ION N Nam STRANG Inventor EM A llorney Dec. 19, 1950 J. M. STRANG SUBMARINE PERISCOPE 4 Sheets-Sheet 5 Filed Oct. 26, 1946 IYQH' N Mmmw STRANG Inventor Dec. 19, 1950 J. M. STRANG SUBMARINE PERISCOPE 4 Sheets-Sheet 4 Filed Oct. 26, 1946 Inventor J OH N MART! N Shzrwe 15;. A ltorney Patented Dec. 19, 1950 SUBMARIN E PERISCOPE John Martin Strang, Glasgow, Scotland, ass'ignor to Barr & Stroud, "Limited, Glasgow, "Scotland Application October 26, 1%6, Serial No. 705,921 In Great Britain May 12, 1945 Section 1, Public Law 690, August :8, 1946 Patent expires May 12, 1965 2 Claims. 1

A submarine periscope comprises an elongated vertical tube with a window or windows at or near the upper end of the tube. It is found that if the periscope window has been-submerged in cold sea water and is then exposed to a warm humid atmosphere, atmospheric moisture tends to condense on the outside surface of the window and to form a which obscures vision.

'It was proposed a .good many years ago to clean a 'periscope window lay the discharge of ah under pressure from the interior of the ship on to the outside surface of the window. In our experience of periscope construction we have never known of such periscope window cleaning systems "being adopted in practice. Experiments with such systems have shown us that a number of practical considerations require to be provided for and present some difficul-ty. Among these are the problem of eifec tively preventing the entrance of water through the air supply conduit when the peiiscope is submerged, and the proper disposition and design of the conduit itself.

The present invention refers to submarine 'periscopes having a window cleaning system of the type by means of which air under pressure is conveyed the interior of the ship and discharged onto the outside surface of the window or "windows.

According to this invention, the window -c;leaning system comprises a non return valve arrangement in the air-delivery conduit at a posinear the window for closing the system against the entry of water when the instrument is submerged, but allowing discharge of the window and in that case the valve arrangement may advantageously be located in the :downwardly extending part of the conduit above the window.

A single non-return valve arrangement may not be completely efiective to close the system against the entry of water, and we find it preferalole to provide a second non-return valve arrangement in "the system at a position lower down than the first valve arrangement.

The construction of such a non-return valve arrangement is important, as there is a tendency for the valve, if it effectively resists the entry of water, to oifer too great a resistance to the supply of air and thus to act as an air pressure reducing valve. With this in view we have designed a 'tion of motion of the submarine.

non-return valve arrangement of flap aconstruw tion, i. e. comprising a :fiap of zfiexilale material which opens and closes by its itlexure relative to a valve seat. 7 A spring :may in some cases he provided against which the flap opens, to :assist in keeping the ilap closed when theexternal ipressure is less than the internal pressure.

-A submarine periscope is usually mounted :so as to he capable of being raised and lowered relative to the ships structure and our window cleaning system is designed accordingly.

We have found in practice that tuhing led up the rear of the exterior of a submarine periscope tube is liable to vibrate severely in the traa isirerse direction as a result of its passage through the water. According to a further feature of our vention, the part'of the "air supply tubing which is located at the rear of the exterior of the 'peri- V scope is of a cross section which is elongated m flattened in a direction transverse to the direca result it can lie very closely against the periscope tube, it is strong in the transverse direction to resist the tendency to vibrate, and it is also less vulnerable than tubing of circular cross section.

Two examples of window cleaning systen'ls accordance with the invention "will now be described with reference to the accompanying drawings, Figures 1 to 8 illustrating one example and Figures =9 to 1'5 illustrating the other ex-- ample. In the drawings:

Figure 1 is a diagrammatic view showing the periscope as a whole,

Figure 2 is a side elevation, partly in section, showing the upper part of the periscope on a larger scale.

Figure 3 is a sectional elevation showing the lower end of the per'iscope.

Figure 4 is a horizontal section :of the *periscope near the lower end .of Figure 2,,

Figures 5 and :6 are two views of a lower end fitting,

Figure '7 .is an elevation showing an air distiibu'tor, and Figure 8 is a face view of the periscope "top,

Figure 9 is a diagrammatic view showing the per'iscope as a whole,

Figure 10 is a side elevation partly in section showing the upper part of the periscope on a larger scale,

Figure 11 is a side elevation showing the top of the periscope in section,

Figure 12 is a side sectional view showing a;

non-return valve arrangement,

Figure 13 shows a detail of the valve,

Figure 14 is a horizontal section of the air supply tubing, and

Figure 15 is a horizontal section through the periscope near the top.

Referring first to Figure 9, the periscope is of elongated tubular form with a lower portion A and an upper portion B of smaller diameter. At the top of the upper portion B there is a window 0.

The window cleaning system, Figures 9 to 15, comprises a connection piece I at the lower end of the periscope, air supply tubing 2 extending up the inside of the lower portion of the periscope, air supply tubing 3 on the outside of the rear of the upper portion of the periscope and connected with the inside tubing 2, a lower non-return valve 4 incorporated in the connection between the tubing 2 and the tubing 3, an upper non-return valve 5 where the air' supply conduit passes over the top of the periscope and a downwardly directed air discharge nozzle 1 at the upper edge of the window C.

The tubing 2 up to the position I5, Figure 2, is made of plastic material having a certain degree of flexibility, while the tubing above I5 is made of metal. The external tubing 3 is made of transversely flattened section as shown in Figure 14. Figures 9, 10, 11 and 15 show how the tubing 3 can lie closely against the periscope tube, the tubing 3 being at intervals securely held to the periscope by clamp rings 24, see Figures 9 and 15.

The non-return valve 4 is of a type already broadly known per se and comprises a valve seat located between gaskets 26, 21. The inside gasket 26 is a disc with a circular central aperture. The outer gasket 27 is of the form shown in Figure 13, being circular with a valve flap 28 in the centre formed by a horse-shoe shaped cut in the material. The valve seat 25 has ports 29 with a total area equal to the cross-sectional area of the air supply tubing. Under the action of the air, the flap 28, being flexible, can swing away from the valve seat and allow the air to pass around its edge into theupper tubing, while if water gains access to the upper tubing its effect is to hold the valve flap against its seat. The upper non-return valve arrangement 5 has a similar construction of combined gasket and flap 27a.- In this case, however, a spring 30 is provided to keep the valve flap closed against light external pressures. A similar spring may be fitted in the valve arrangement 4. The valve construction shown having the relatively small ports, permits the use of a thin flexible gasket; this allows the valve to open and shut rapidly with reversal of pressure and prevents it being distorted by sea pressure or back pressure and causing leakage.

The connection piece I at the lower end of the periscope provides for the attachment of a flexible air supply pipe 31, for instance from a compressed air bottle. The air supply system from i up to the window is carried entirely by the periscope, and throughout the lower part A of the periscope thesystem is internal. Thus it does not interfere with any of the standard arrangements for raising and lowering the periscope relative to the ship.

Figures 1 to 8 show another example which is very similar to that already described except 4 that the non-return valve arrangements 4 and 5 are of spring-loaded ball type. The springloaded ball I6 is adapted to open only in the upward direction.

At the position [8 the air tubing passes from the inside to the outside of the periscope through the medium of metal blocks I9, one on the outside and one on the inside of the periscope wall. Near the top of the periscope there is a distributor 6 from which two nozzles I extend over the top of the periscope and are directed downwardly to the upper edge of the window C, see Figures 7 and 8. Optical parts D, such as lenses, within the periscope are notched, as shown at 8 in Figure 1, to allow of the passage of the air tubing 2. The connection piece I, see Figures 5 and 6, is secured to the lower end of the periscope by screws l2. It comprises a nipple 22 for the attachment of the flexible air supply pipe, and a cock 23 for closing the fitting.

Iclaim:

1. A submarine periscope having a window cleaning system comprising an air pressure source and an air delivery conduit containing air under pressure arranged to discharge said air against the periscope window to clean the same, a non-return valve interposed in said conduit at a position in close proximity to the periscope window, said valve comprising a housing fixed t0 the periscope, a perforated plate within said housing in communication with said conduit, said conduit being directed towards the periscope window, a flexible flap engaging said plate to close said perforations and conduit against entry of water past said valve, means for pressing said flap against said perforated plate, said flap opening under pressure from said conduit to allow for the discharge of the pressure cleaning air to the outer surface of the window when the periscope is above water, the

air under pressure being constantly directed against said flap and being resisted by said flap pressing means, said pressure of air being sufficient to overcome said resistance and discharge said air against said window when said window is above water, but being insufiicient to overcome said resistance and water pressure against said flap when the valve is submerged, so that the valve remains closed when the submarine is submerged.

'2. A device according to claim 1 in which a portion of said air delivery conduit is disposed at the rear of the exterior of the periscope and is substantially elongated in cross section, the elongated sides of said conduit being arranged in a plane substantially at right angles to the longitudinal axis of the submarine.

J. MARTIN STRANG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 759,622 Lake May 10, 1904 767,624 Bedell et al Aug. 16, 1904 1,072,398 Langley Sept. 2, 1913 1,222,156 Steinmetz Apr. 10, 1917 1,697,257 Anissimoff Jan. 1, 1929 2,163,506 Tucker June 20, 1939 

